Format for the "Geographic Resources Analysis Support System" (GRASS) raster-oriented package, originally developed by the US Army Corps of Engineers, and still surviving as open source after being abandoned by the Army in 1992 and being taken over first by a team at Baylor University and, more recently, OSGEO.   The Manifold GRASS dataport reads raster data from GRASS.  


GRASS files typically come in hierarchies of folders containing many constituent files, where the location of various files within the hierarchy has meaning for the original project when opened in GRASS.   It can be a major challenge for people who are not in the GRASS subculture to figure out what files contain data of interest.



To import from GRASS format:


  1. Choose File-Import from the main menu.

  2. In the Import dialog browse to the folder containing data of interest.

  3. Choose . Files (GRASS) (*.*) in the file type box.

  4. Double-click the file for the data of interest.

  5. A table and image will be created.




We can double-click on an image to view it.



GRASS can work with raster images in a very wide variety of formats.  Opening an image may require significant tinkering with Style settings, such as utilizing Full Range on channel values, to create a visually meaningful image.   For example, the elevation image opened above consists of a single channel that seems to give the elevation value for each pixel.




We have used Style to apply a palette to the image, along with hill shading.   Unique values have been used to color each of the elevation values found in the data with the CB Spectral palette in reverse order.



The result is a better, more visually understandable image.


See Also











Example: Spectacular Images and Data from Web Servers